Two or more blades are connected to the hub, and the blade surface is a screw surface or similar screw surface Marine propeller ,it is called commercial customized marine propeller.
the commercial customized marine propeller includes many parts. The propeller is installed below the waterline at the stern, and the main engine gets the power and rotates, pushing the water behind the ship, and using the reaction force of the water to push the ship forward. The marine propeller is simple in construction, light in weight, efficient and protected below the waterline
The number of commercial customized marine propellers can be increased for a powerful ship. Large fast passenger ships have two to four OARS. The diameter depends on the horsepower and draft of the ship. The bottom end does not touch the bottom and the top end does not exceed the load waterline。The commercial customized marine Propeller materials are generally made of manganese bronze or corrosion-resistant alloy, stainless steel, nickel-aluminum bronze or cast iron.
Since the 1960s, ships tend to be large, and after the use of high-power main engine, The commercial customized marine propeller induced stern vibration, structural damage, noise, erosion and other problems caused by the propeller excitation have attracted the attention of various countries. The root cause of propeller vibration is the increase of propeller blade load, and the local unstable cavitation is easy to occur when the propeller works in the uneven wake behind the ship, which leads to the constant changes of propeller pressure, amplitude and phase acting on the hull.